Insulator



Patented Jan. 15, 1924.

UNITED. STATES PATENT OFFICE,

ARTHUR 0. aus'rm, OF BARBERTON, OHIO, nssrenon, BY mnsnn ASSIGNMENTSQTOTHE OHIO BRASS; COMPANY, OF MANSFIELD, OHIO, A CORPORATION or NEWJERSEY.

msuLa'ron.

Application filed'Aprfl 10,

To all whom it may comm/m:- f p Be it known that I, An'rrjun U. Aus'rln,a citizen of the United States, residing at Barberton, in the county ofSummit and 6 State of Ohio, haveinvented' certain newand usefulImprovements in Insulators, of which the following is a specification.

This invention relates to 'insulating"devices and especially toinsulating devices designed for'use with high potentials, andhas for itsobject the provision of insulatorswhich shall provide improvedmechanical strength for the amount 0f material em- I ployed withoutsacrificing electrical 'efliciency' andwhich shall be of improvedcOnstruc-' tiona'nd operation. p y y The invention is exemplifiedin thecombi-; nation and-arrangement of parts shown in the accompanyingdrawing-and described; in the following specification; and'it is'mo'reparticularly pointed out 'in'the appended claims; I ;1 2 l In 'thedrawing; the figurerepresents an insulator embodying oneforui ofthe'=p1'esent invention shown partlylinelevation and partly in section.-In'. the embodiment shown the dielectric or insulating material isintthe former a hollow tubel which is representedias" being ofnnifor mdiameter throughout. The tube; I may; however, be of various shapesto'givel strength and convenience in maniufacture. Various insulating,materials t nny be em ployed, one material in co'm mon ;u'se being; 3bporcelain and other vitreous materialsgf'such, as glass, are sometimesemployed; M00111. nected with the tube, adjacent the OPPOSitQ endsth'ereo fiare hollow metallic members? 2 and 3 which. are provided witheyesl'or; other fastening devices 4 and 5, respectively by means ofwhich the insulator is "secured to the parts to be insulated. Theinembel; 2

y is intended to be connected with'the ground ed sup ort while theinemberB iscOnnected with t e charged conductor. The members 2, and 3aresecured to thetube rat points spaced from the ends. ofthe tube, as shownatthe' leftfin the'drawing. iThejoint between thecap 3 and the tube 1maybe e ffected' in an of the usual anda'p'proved ways for ma iing suchfconnections; 1t? being common practice to employ a? grade I of'Portlandor .other cementior this urpose, as's'hown at 6 in'the' drawing. e

'tliecenter of t e tube'w ichftends to dry 191 Serial 1%. 289,091.

surfaces Of the tube 1 and the cap 3, which are engagedby the cement,are preferablvj roughened to insure firm connection with the cement.Under certain conditions of operation the: tubular insulator is verydesirable for the 6 reason that a tubular section gives a highlyefficient distribution of the material tore-j sist bending strains setup by vibration of the insulator'and connected parts and for otherreasons; It has been found, however 65 that where tubular insulators areemployed there isa tendency'to' discharge through the center 'of thetube and especially is'thisH true if moisture collects within thet'ube.

It is very' desirable to avoid sucha central flash-Over or discharge,for" the reasonjthat adischar e through the tube almost invariablyresults inian explosion of the, tubular member the least. disastrouseflect of whic'h is the destruction 'of the insulator. I An Ou tQ- 7side dischargejhoweveriis usual] l-ficcom- Panid bi l t le f I Q s I aco necting caps are secured directly to the ends of 'a" tube. insulatoran discharge or flash-- over is very apt to ta e'place through thecenter of the jtubef for the reason that; t e'j path through the centeris as'sho' l; Q1? Shorter a the uts de P th and i r if ii thatatmosphericlcondition's within the tube; arelikely' to'befsuch as toOfl'er lessfresistance 86 tofa ilischarge than the atmosphere utside thetube; A baflie or webiof insulatingnm j trial maybeeittended' across thetube for the purpose of decreasing the liability of dis:- chargethroughthe center, but under certain conditions this barrier malyfdefeat its own purpose, If, for instance,moisture accumw. lates "withinthe tube, then practicallythe entire drop of' potential betweenthe endsof the tube occurs in thejshort' space occupied by the baflle web,' forthe} reason that this y'vebap rokimat'ely an"infin iteiresi stj ancecom'p'ar'e with the resistanceof' the remaining portion of the interiorof the 'tube', and as a' result the entire pressure is c'o'n-'centiflated' upon the web "and the web is; siie'rced and; an intern'aldischarge results? iipli' across web also: interferes with the; flowofcha rgin or'lealra e current through an" j 'ni oisture whichaccumulates within the tu e." A 'web of this kind also interferes withthe circulation of atmosphere within the tube and tends to set upatmospheric conditions favorable to flash-Wei.

In the present invention the tendency to discharge through the centerof. the tube is overcome by connecting the end ca) at a point spacedinwardly from the cut of the tube and by forming the cap so that everypoint thereof is located at a considerable distance from the opening atthe mouth of the tube. The cap mey be shaped so that approximately allthe points of the cap will have the same resista n c i between them andthe mouth of the tube his menus that the oint of content between the capand the time is spaced a greater'distance from the end of the tubetheriI the points in the cap nearer the end of t e insulator. The reasonfor this is that any lcuka ge from the point: of contact between the capand the tube will extend qlong the surface of the ube inst ad of across]an air-gen, A s: charge from poin s QPPO it he. open end of the tubemust puss through the sun spafi be ween e p a d t ube, we hen sp'ce;between the cap, end the end. of the hi e at e e peint efed n t be $9 geet e. mis s edia ehfi t -h w't e we n the cen nd th tube A disrhmrgefrom, any intermecliat .pqi11t in'thec'eP would probably ak 1; h r p rty through we aimed partly e long the surface of tube sov that the, zipwould gradually diverge tram the surfe ce otthe tube as it extendstoward the end of the. insulator. A c ap designed, there e o i n prximate i m esiste ee t shwe f a u i i in the cup to the center ofthe'tube would have u shupe similar to that shown in the drawing. Thisshape. also is desirable. from mech ni s ndp int e it s Wei suited to hths ei l t t P a d W1 9 t e r by the tension exerted 'upon the eye. 5.It

will be understood, of course, that other shapes of connecting capfn eybe employed without sacrificing the benefits of resistance due to thespacing of thc'uzallsof the. cap r m e end 0 e ube, r i s nce acylindrical cap could be used connected to. the tube by wall members atits innr $1.1 1 extending inwardly to the tube at right 2141- gles to tsexis and various other shapes buld he empleyed- It is desirable formqliy reasons that a free circulation 0t air. through the. center of theinsulator may be possible, for otherwise the air within the insulatormay be a-ixe ctedby' the electrical stresses so as to produce pgessurewithin the insulator, or. to ecreas t e 'stwee te'fl shve ir la o of hea r t l g i'the s lator it :i ite e y es t he, etefibi; f he W t-Pd th sec ases. he 'e de cy 0 ee geend discharge '3 free 011;.- hhe; er en"t-hie flea ii'llteire in; hie -t s eless iie e u. m us ssmwl 7 may beconne'ted with the end cups 2 and 3, these breathers being. constructedto exclude water from the interior of the insulntor but to permit freepassage of air. The end, f h br ather tube 7, may b enclose in a mber 8having peripheral perf tions 9 through which 'water may escepeindependently of the position of the insulator and the tube 7 preferablyextends :1 short distance into the chamber 8 and is provided at its curlwith a circumferential head 10 to collect water of condensution andprevent its entering the insulator through the tube 7.

The flash-over of a high tension insulator depends to, a great extentupon the distribu: tion of electrostatic flux of lines of force andwhere a. concentration of the electrostatic lines of; force is permittedthere is danger; of a power discharge along. the path of these lines, offorce. It is therefore desirable, to distribute the electrosstaticfluxas nearly evenly. as possible in order to pre: vent it wnfi ntmtion0f the lines of force at ne mih For t is reason an elec rostatic re n,-hown at 11 in, the d ew-hug, s. onnect d to. the nd ap 3 and exte ls ouwardly from its point of connection with the n mp an t ard. the oppos teend of the insulutor. The. electrostatic sc een 11 is p e rab y made ofQpen c nstruction. havn arms 12 which carry-e u i rmly curredcircularrim 13 a their forwa end the rim 13 surrounding the tube 1 andspaced ad a yhe tu eith this arr n e t h .eletwst tic u is. cause to emm"ate substantial y u i rmly om the sur face of the rim 13 so that thereis no conentm ien o flux, at any one n iut, i u consequent tendency toflash-owl from that point- The. Open construction of the creen pe s owas i g by r the hen e thefscreezr is kept clean by its exposure to hWhether l hile the cogcnegto s. 2 and 3. are shown in he drawing, as soid shells, they t ey, f cour e, b of open r k le n on true: tion withoutlosing the. adrentuge of having he parts 0; the connectors spaced fromthe end 0 ub lar insule qlf member. when an 0 en construction is used,the breuthers wil of course. not he. necessary.

I c aim An. insulator comprising u tube, o,[ insuleting inete 'ielhaying gm open end, l; pair, of comicctin members. secured to, the. ut-ssurfaced Shir ih edi 'e ht h -12 posite. en ds, thereoi and insulatedfrom one. wi her 9 w. 9i e eiebiit his 1 wi eless-d to. engage tubeonly; at poi sudjecent e end. ens teem R e 2- he. m eite t eemriiees etu er i s an ori ng est hsllg ietls e h sh hr eh.

nd Beer 9 t e m m r sec re to th we ite 0 s e tu and. web d fine ne miks o e f ed. meshe be:

ing arranged to engage said tube only at points spaced inwardly from theopen end thereof.

3. An insulator comprising a tube havlng the end thereof open, and apair of connectin members secured to the outside of said tu e andinsulated from one another thereby, one of said-members being arrangedto engage said tube only at points spaced inwardly from the open endthereof, said connecting member having all points thereof spaced fromthe end of said tube.

4. An insulator comprising an integral elongated insulating memberhaving an opening therethrough, and a mechanical connector cap disposedentirely externally of said member and secured to said member adjacentone end thereof, said cap having all of the points thereof spaced fromthe end of said insulating member.

5. An insulator comprising a tubular insulating member having the endthereof open, and a mechanical connector cap secured to said memberadjacent said end, said cap being disposed entirely externally of saidmember and arranged to surround the open end of said member and havingthe walls thereof spaced away from the end of said member.

6. An insulator comprising a tubular in sulating member having an openend, and an external connector secured externally to said member at apoint spaced inwardly from said end, said connector extending from itspoint of connection with said insulating member outside of said memberpast said end and having all points thereof spaced from said end.

7. An insulator comprising a unitary tubular insulating member having afree passage extending therethrough, end caps secured to the outsidesurface of said member and enclosing the ends of said member and havingthe walls thereof spaced from the ends of said members at all points ofsaid walls.

8. In an electric insulator, an insulating mechanical load carryingmember comprising a unitary tube of vitreous material having an openingextending therethrough, and external mechanical load carrying metal endcaps secured to said tube externally thereof and adjacent the endsthereof, said caps having the walls thereof spaced from the ends of saidtube, said tube being the only mechanical connection between said endcaps.

9. An insulator comprising a tubular insulating member, an end capsecured to said member at a point spaced inwardly from the end thereof,the Walls of said cap being shaped to diverge outwardly from saidinsulating member and to extend toward and surround the end thereof sothat all points in the walls of said cap are spaced from the end of saidmember at distances to effect approximately uniform resistance to flashover between the various points in the walls of said end cap and theopen end of said tubular insulating member.

10. An insulator comprising a tube of insulating material having an openend and a pair of connecting members secured to the outer surface ofsaid tube adjacent the opposite ends thereof and insulated from oneanother, one of said members being arranged to engage said tube only atpoints adjacent to and spaced from said open end, and a fluxdistributing screen secured to one of said connecting members andextending outwardly from said tube and toward the opposite end of saidmember.

11. An insulator comprising a tube having an opening extending entirelytherethrough and a pair of connecting members secured to the outside ofsaid tube and insulated from one another, one of said members beingarranged to engage said tube only at points spaced inwardly from theopen end thereof, and an electrostatic screen secured to said connectingmember and extending toward the opposite end of said tube and outwardlytherefrom.

12. An insulator comprising a tube having the end thereof open, a pairof connectin members secured to the outside of said tufie and insulatedfrom one another thereby, one of said members being arranged to engagesaid tube only at points spaced inward y from the open end thereof, saidconnecting member having all points thereof spaced from the end of saidtube, and an electrostatic screen secured to said connecting member andextendin toward the op posite end of said tube an outwardly therefrom,said screen having a curved rim surrounding said tube at the portion ofsaid screen farthest removed from said connecting member.

In testimony whereof I have signed my name to this specification on this3rd day of April, A. D. 1919.

ARTHUR O. AUSTIN.

